Electrochemical behaviour of nickel electrodes modified with nitrophenyl groups

The electrochemical modification of the Ni electrode surface with nitrophenyl (NP) groups was performed by the diazonium reduction method. For the first time the barrier properties of NP-modified nickel surfaces were characterized using Fe(CN)63-/4- as a redox probe. Electrochemical measurements were carried out in 0.1 M KOH containing 5 mM K3Fe(CN)6 using cyclic voltammetry and the rotating disk electrode (RDE) technique. The nitrophenyl groups are strongly bonded to the nickel surface since they can withstand sonication in acetonitrile. The results of the X-ray photoelectron spectroscopy (XPS) analysis confirmed the irreversible attachment of nitrophenyl groups onto the nickel electrode surface.